60 citations · 238 across the 20 of their papers we have counts for
17 papers · 1 filter
A practical approach to perturbative corrections to few-body observables
Sourav Mondal, Martin Schäfer, Mirko Bagnarol +3
We formulate two methods to facilitate the calculation of perturbative corrections to quantum few-body observables. Both techniques are designed for a numerical realization in comb…
Scale-(in)dependence in quantum 4-body scattering
Sourav Mondal, Rakshanda Goswami, Udit Raha +1
We investigate the multi-channel 4-body scattering system using regularized 2- and 3-body contact interactions. The analysis determines the sensitivity of bound-state energies, sca…
Calculation of Dynamical Response Functions Using a Bound-state Method
Niels R. Walet, Jagjit Singh, Johannes Kirscher +3
We investigate a method to extract response functions (dynamical polarisabilities) directly from a bound-state approach applied to calculations of perturbation-induced reactions. T…
Emergence of H resonance in contact theories
Lorenzo Contessi, Martin Schäfer, Johannes Kirscher +2
We obtain the - and -wave low-energy scattering parameters for nH elastic scattering and the position of the H resonance using the pionless effective field…
Two Particles with Zero-Range Interaction in a Magnetic Field
Johannes Kirscher, Brian C. Tiburzi
Energy levels are investigated for two charged particles possessing an attractive, momentum-independent, zero-range interaction in a uniform magnetic field. A transcendental equati…
Emergent four-body parameter in universal two-species bosonic systems
Lorenzo Contessi, Johannes Kirscher, Manuel Pavon Valderrama
The description of unitary few-boson systems is conceptually simple: only one parameter -- the three-body binding energy -- is required to predict the binding energies of clusters…
Multi-fermion systems with contact theories
Martin Schäfer, Lorenzo Contessi, Johannes Kirscher +1
We address the question of minimal requirements for the existence of quantum bound states. In particular, we demonstrate that a few-body system with zero-range momentum-independent…
Asymmetric regularization of the ground and excited state of the helium-4 nucleus
Johannes Kirscher, Harald W. Grießhammer
We find the threshold structure of the two- and three-nucleon systems, with the deuteron and 3H/3He as the only bound nuclei, sufficient to predict a pair of four-nucleon states: a…
Emergence of a Brunnian neutron state
Johannes Kirscher
We discuss a quantum-statistical feature of non-relativistic identical fermions whose interaction is predominantly attractive at low energies. Specifically, we consider exotic, mul…
Electromagnetic characteristics of physical and lattice nuclei
Johannes Kirscher, Ehoud Pazy, Jonathan Drachman +1
We analyze the quark-mass dependence of electromagnetic properties of two and three-nucleon states. To that end, we apply the pionless effective field theory to experimental data a…
Matching effective few-nucleon theories to QCD
Johannes Kirscher
The emergence of complex macroscopic phenomena from a small set of parameters and microscopic concepts demonstrates the power and beauty of physical theories. A theory which relate…
Spectra and Scattering of Light Lattice Nuclei from Effective Field Theory
Johannes Kirscher, Nir Barnea, Doron Gazit +2
An effective field theory is used to describe light nuclei, calculated from quantum chromodynamics on a lattice at unphysically large pion masses. The theory is calibrated at leadi…
Pionless Effective Field Theory in Few-Nucleon Systems
Johannes Kirscher
A systematic description of low-energy observables in light nuclei is presented. The effective field theory formalism without pions is extended to: i) predictions with next-to-lead…
Constraining the neutron-neutron scattering length with \eftnopi
Johannes Kirscher, Daniel R. Phillips
We compute a model-independent correlation between the difference of neutron-neutron and proton-proton scattering lengths |a(nn)-a^C(pp)| and the splitting in binding energies betw…
Zero-energy neutron-triton and proton-Helium-3 scattering with \eftnopi
Johannes Kirscher
Model-independent constraints for the neutron-triton and proton-Helium-3 scattering lengths are calculated with a leading-order interaction derived from an effective field theory w…
Universal Correlations in Pion-less EFT with the Resonating Group Model: Three, Four, and Six Nucleons
Johannes Kirscher, Harald W. Grießhammer, Deepshikha Shukla +1
A systematic connection between QCD and nuclear few- and many-body properties in the form of the Effective Field Theory "without pions" is applied to nuclei to determine i…
Universal Correlations in Pion-less EFT with the Resonating Group Model: Three and Four Nucleons
Johannes Kirscher, Harald W. Griesshammer, Deepshikha Shukla +1
The Effective Field Theory "without pions" at next-to-leading order is used to analyze universal bound state and scattering properties of the 3- and 4-nucleon system. Results of a…